Isolation and characterization of a Pseudomonas aeruginosa PAO mutant defective in the structural gene for the LIVAT-binding protein.
A mutant of Pseudomonas aeruginosa PAO which has a defect in the structural gene for a binding protein for leucine, isoleucine, valine, alanine, and threonine (LIVAT-binding protein) was isolated and characterized. DL-4-azaleucine was taken up via the high-affinity branched-chain amino acid transport system (LIV-I), but not via the low affinity system (LIV-II), and then inhibited the growth of P. aeruginosa cells. This finding enabled us to select mutants defective in the LIV-I transport system alone. Among such mutants, strain PAO3530 was found to produce an altered LIVAT-binding protein. The shock fluid of this strain contained a normal level of the protein which corresponded to the wild-type LIVAT-binding protein as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by an immunological test. However, the shock fluid showed almost no binding activity for branched-chain amino acids, suggesting that strain PAO3530 has a defect in the structural gene for the LIVAT-binding protein. The mutation locus (bra-310) was mapped in a region between cnu-9001 and oru-325 on the chromosome of P. aeruginosa PAO by conjugation mediated by plasmid FP5 or R68.45.
D000409:Alanine / Q000378:metabolism; D001426:Bacterial Proteins; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics*; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D005796:Genes; D005798:Genes, Bacterial; D007532:Isoleucine / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000378:metabolism; D013912:Threonine / Q000378:metabolism; D014633:Valine / Q000378:metabolism
D001426:Bacterial Proteins; D002352:Carrier Proteins; C035178:LIVAT-BP protein, Pseudomonas aeruginosa; D007532:Isoleucine; D013912:Threonine; D007930:Leucine; D014633:Valine; D000409:Alanine